This grant is to provide various degrees of partial or core support for a variety of projects related to the cochleo-vestibular system in animals and humans. Specific research topics include the distribution of fibers and the fine structural characteristics of the vestibular nerve and nuclei; the localization of sound in space; various aspects of the auditory evoked response; the mechanics of thermal vestibular stimulation in the cat; the effects of ototoxic drugs upon the central nervous system; various aspects of the acoustical impedance of the middle ear in man; the effects of high energy radiation upon the Eustachian tube and middle ear; the histologic changes occurring in the human inner ear in response to disease; and abnormalities of auditory perception in children with middle ear impairments.